1. Field of the Invention
The present invention relates to sugar cane harvesting, and more particularly relates to an improved boom and grapple configuration for use with sugar cane loaders wherein the boom axis and grapple jaw closure path axis are skewed at an acute angle with respect to each other so that the loader and a cane cart can be maintained side by side during loading, spaced a row apart to improve cane quality by eliminating cane muddying or damaging because of mud splashing or rollover. In the method of operation, cane wholestalks are lifted upwardly with the boom and grapple from an initial position on the ground surface of a sugar cane field, and the boom travels a short approximate ninety degree (90.degree.) arc to discharge the cane wholestalks at a second elevated position where the cane falls into a cart. The improved configuration allows the cane cart and its hauling tractor to remain one row away from the cane heap being loaded, eliminating the possibility of rolling on the cane or of mud being splashed upon the cane heap row, resulting in a cleaner cane product at the mill.
2. General Background
In the harvesting of sugar cane, each stalk of cane is typically cut at the bottom and at the top, creating a cut "wholestalk", and then wholestalks are piled into "windrows" wherein the cane is piled normal to and atop two adjacent rows, spanning a furrow. In the hand harvesting of sugar cane, each stalk is cut at the bottom and at the top, and some of the time once or twice in the center portion of the stalk. These large sections of cane are still referred to as "wholestalks". Cane wholestalks are piled generally parallel to one another, each stalk extending across the raised soil rows of the cane field, straddling the rows where the cane was initially standing and growing.
Several devices have been patented which describe the mechanical methods and apparatus used to harvest cane and to place it in "windrows", which are stacks of cane perpendicular to the rows. The Duncan U.S. Pat. No. 4,380,281 for example entitled "Associated Running Gear and Piler Improvement in a Two Row Harvester and Piler" relates to a sugar cane harvester which cuts the cane at its top and bottom and thus produces wholestalks. A wholestalk as used herein refers to a stalk of cane which is cut at its base near the ground, and at its top to remove leaves, but which has not been cut into several smaller pieces or "billets". Wholestalk harvesters such as the harvester shown in the Duncan '281 patent cut and then pile the cane in generally parallel fashion, perpendicular to the rows. These harvesters are also known as "soldier" harvesters because the cut cane is maintained in a vertical position, one stalk following the previous stalk (like marching soldiers) often being cut and prior to piling. A cane loader which addresses the problem of accumulating cane wholestalks into bundles is disclosed in U.S. Pat. No. 4,609,318 entitled "Rotary Piler System For Sugar Cane".
U.S. Pat. No. 3,475,886 entitled "Method of Harvesting Sugar Cane" shows a harvester which uses a constant discharge of cut cane to the left hand side of the harvester.
Other examples of cane harvesting and piling equipment include the Pugh U.S. Pat. No. 2,669,829 entitled "Cane Harvesting and Piling Machine" the Thompson U.S. Pat. No. 3,090,183 "Process for Harvesting and Piling Cane", and U.S. Pat. No. 3,448,564 entitled "Cane Harvester". These cane harvester patents are exemplary of various machines that can be used to cut and pile cane and are exemplary of cane harvesting equipment in general. Hand cut cane, also referred to as "wholestalk" cane is handled in the same basic way.
When wholestalk cane has been windrowed, it must then be lifted and placed into cane carts or trucks for delivery to the sugar cane mill. Several devices are now commercially available which are used to gather and load the cane. These gathering devices are typically referred to as "cane loaders". One of the most common types of loaders is simply a wheeled device which carries a movable boom having a grapple formed by opposed grabbing tines mounted at the end of the boom. The tines are usually hydraulically powered and operate much like a crab claw to grab large batches or bundles of the cane. The closed tines are lifted by the boom to transfer the gathered cane up into the air and deposit it into large cane carts or trucks.
One of the problems with cane gathering devices is the problem of the unintentional mixing of mud, dirt and rocks with the cane which produces a reduction in sugar extraction, higher processing costs and an expensive cleaning problem at the mill. Water must be used to clean the cane of mud. This muddy water becomes a potential source of water pollution. Thus there is a need for an efficient "clean" cane loader. Because of the proximity of the cane loader to the cart (usually pulled by a tractor), the cane stalks can be muddied by the simple splashing of mud. Sometimes the tractor/trailer rolls over the cane stalk ends causing damage and/or extensive muddying of the cane.
Several cane loaders are commercially available. One commercial embodiment of a four wheel drive, self propelled cane loader is the Cameco SP 1800 model loader manufactured by the assignee of the present invention, Cameco Industries, Inc. The Cameco SP 1800 is a hydrostatic drive, self propelled cane loader with an articulated boom mounted on the frame of the loader. The boom includes a forward end portion with a pair of spaced apart powered tines which are hydraulically actuated to open and close. The tines are fixed so that the travel path of the tines is aligned with the boom axis. In another version of the SP 1800, the tines are rotatably mounted with respect to the end of the boom.
A commercially available continuous loader is the Cameco model R-6 which uses endless inclined chains mounted upon sprockets for lifting the cane stalks from the ground. After the cane is picked up by the chains it is cut into billets. Two blowers and two extractors remove leaves and dirt that was attached to the cane.
Some commercially available loaders use a forwardly inclined scoop in combination with gathering chains to the cane stalks from the ground surface. The scoop includes a forwardly curved section which redirects the cane forwardly so that continuous operation of the device tends to roll the cane into an ever increasing bundle which constantly communicates with the scoop. Thus the cane never leaves the scoop until it is ready for loading.